Plate clamp



July'13, 194-3. CHANDLER 2,324,362

v PLATE CLAMP Filed June 15, 1942 10 E I l5 i 4 W Q 37 +1 42 29 I V 4 24o -30 INVENT OR.

* 2715. Chandler- BY flTTOR/VEY Patented July 13, 1943 UNITED STATESPATENT UFFICE 2,324,362 PLATE cLAMP Tommie B. Chandler, Compton, Calif.

Application June 13, 1942, Serial No. 446,969

6 Claims.

My invention relates to a plate clamp and more particularly to a camtype clamp for lifting heavy plates in ship building and in otherindustries.

It is an object of my invention to provide a lifting device that willmaintain a clamping means against the plate, whereby the plate will notbe accidentally dropped, even though the lifting means is temporarilyreleased.

Heretofore, lifting means for steel plates have been released when thelifting cable is accidentally released, as when the plate accidentallystrikes an object during the lifting operation. In such instances, themechanism heretofore employed has released the plate, thereby droppingit and causing injury. It is an object of my invention to provide meansto prevent the accidental dropping of the plate, even under thecircumstances described.

My invention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed in a workingposition and easily disconnected therefrom, economical of manufacture,relatively simple, and of general superiority and serviceability.

The invention also'comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description.

However, the drawing merely shows and the following description merelydescribes one embodiment of the present invention, which is given by wayof illustration or example only.

In the drawing, like reference characters designate similar parts in theseveral views.

Fig. 1 is an elevational view, partly broken away, showing an embodimentof an invention carrying out the foregoing objects.

Fig. 2 is a side elevation of said embodiment, showing the lower portionin vertical section.

Fig. 3 is an enlarged section of the lower portion of Fig. 2, showinglocking means in a diiferent position than shown in Fig. 2.

Fig. 4 is an enlarged section taken on line 4-4 of Fig. 2.

Fig. 5 is a perspective view of said embodiment in an operativeposition.

Fig. 6 is a perspective view of the sliding lock member hereinafter morefully described.

Referring more in detail to the drawing, the reference numeral 1generally designates a U- shaped body for said lifting device. As shownin Fig. 2, the body '3 may be made up of side plates 8 and 9 with aspacer plate I0 therebetween. However, it is believed clear withoutfurther illustration that the side plates and spacer member it! may be asingle, integral member. The body member 1 has a loop 12 extending atvan angle therefrom. A cam 53 is disposed between the side members 8 and9 of the body and pivoted thereon by means of the axle Hi. The outwardlyextending portion of the cam !3 has an eye 15 through which cable It ispassed for operating the cam 13. The cable it extends through the loopit. The end of the cable that passes through the eye i5 is joined toitself as shown at ll.

The loop I2 is so arranged laterally of the body I that when the cablei6 is drawn through same in a direction of the arrow B, the cable movesthe cam to a locking position. After the cable extends through the loopl2, it may be practically drawn in any direction and still lock the cam.1

A fiat plate I8 is shown being gripped by the teeth iii of the cam 53,between jaws 2b and 2! of the body 1.

To maintain the cam in a locked position, against accidental slippage, awedge lock 22 is slidab-ly supported in a channeled member 23. The lock22 has a wedging face 24 for engaging the cam I3 in any locking positionof the cam, within the limits of the wedging face. I

A. spring 25 coiled about a threaded end 25 of the wedge-shaped lock 22abuts against a nut 2'. on the threaded end 28 and against the sidemember 9, thus tending to move the wedge 22 toward a locking positionwith respect to the cam iii. A cotter pin 23 passing through the nut 21and through the threaded end 25, holds the nut in adjusted positions. Atubing 28 provides a housing for the spring 25 and threaded end 26, andacap 39 on the tubing affords a stop for outward movement of the threadedend 25. Filler members 3! brace the lower portions of he side members 3and 9 in spaced relation.

A latch having a pivot 33 and urged by a spring 3 retains the wedge lock22 in a retracted position when its prong 35 engages a recess 3B in thewedge lock 22. The prong 35 is shown in such engaging position in Fig.2. A button 3! on the latch 32 is depressed in the direction of thearrow A in Fig. 3 to release the wedge lock. Upon release, the wedgelock moves to the position shown in Fig. 3, unless the wedge face 24sooner engages the cam l3. A thumb opening 38 in the wedge lock 22provides means for an operator withdrawing the wedge lock 22 from theposition shown in Fig. 3 to the position shown in Fig. 2. The end of thewedge lock is built up, as at 39, to facilitate this withdrawingoperation. The cam l3 has a beveled portion 40 to conform with the wedgeface 24 not only to increase the amount of friction between the cam andthe wedge, but also to increase the size of the area of wear whereby tolengthen the life of the device.

In the operation of the device, the jaws 20 and 2| are slipped over anedge of a flat plate or other shape of plate l8. The teeth I9 are thenmoved to a biting relation with respect to the plate l8.

The button 31 is then depressed in the directlon of the arrow A,releasing the wedge lock 22, which moves, under the influence of thespring 25, into contact with the cam I3, thereby holding the cam l3against accidental release of the plate I8.

When it is desired to release the plate la, the wedge lock 22 is drawnback until the prong 35 is spring urged into the recess 36, thus holdingthe wedge lock in a retracted position. The cam l3 may then be moved toa plate-releasing position.

The cable [6 is utilized in lifting the present device with its thereingripped plate, or in lifting the device alone, when it is removed fromthe plate.

It will be noted that as long as the cable I6 is drawn in the directionof the arrow B, the end 4| may be pulled around or through the loop l2in almost any direction, without drawing the cam [3 in a releasingposition.

While I have illustrated and described what I now regard as thepreferred embodiment of 3- my invention, the construction is,'of course,subject to modifications without departing from the spirit and scope ofmy invention. I, therefore, do not wish to restrict myself to theparticular form of construction illustrated and described, but desire toavail myself of all modifications that may fall within the scope of theappended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A lifting device comprising jaws to be placed at either side of anelement to be lifted, a cam pivoted on the device and movable into thespace between the jaws to engage work therebetween, and wedging meansarranged to maintain contact with the cam and hold the cam in any lockedposition, within the limits of effective work engaging range of movementof the cam.

2. A lifting device comprising jaws to be placed at either side of anelement to be lifted, a cam pivoted on the device and movable into thespace between the jaws to engage an element therebetween, means arrangedto contact the cam and maintain the cam in any locked position, withinthe limits of such means, and spring means urging said means intocontact with the cam in any of said positions.

3. A lifting device comprising jaws to be placed at either side of anelement to be lifted, a cam pivoted on the device and movable into thespace between the jaws to engage an element therebetween, wedging meansarranged to contact the cam and maintain the cam in any locked position,within the limits of such means, spring means urging said wedging meansinto contact with the cam in any of said positions, and mechanism toreleasably hold the first-mentioned means against the action of thespring means.

4. A lifting device comprising jaws to be placed at either side of anelement to be lifted, a cam pivoted on the device and movable into thespace between the jaws to engage an element therebetween, slidingwedge-shaped means arranged to contact the cam along the wedge-shapedface of said means maintaining the cam in any locked position, withinthe limits of such wedgeshaped face, and spring means urging said meansinto contact with the cam in any of said positions.

5. A lifting device comprising jaws to be placed at either side of anelement to be lifted, a cam pivoted on the device and movable into thespace between the jaws to engage an element therebetween, the cam havinga beveled face at the rear thereof with respect to the direction ofmovement of the cam toward an element-engaging position, slidingwedge-shaped means arranged to contact the cam along the beveled facethereof, in any position of the cam within the limits of such means, andspring means urging said means into contact with the cam in any of saidpositions.

6. A lifting device comprising a work-engaging cam, a lifting cableconnected to operate the cam, a loop on the device at the side of thecam in the direction of the cam-locking movement of the cable, the cablebeing passed through the loop, to effect locking movement of the cameven though the cable is drawn in almost the opposite direction andwedging means arranged to maintain contact with the cam and hold the camin any locked position, within the limits of effective work engagingrange of movement of the cam.

TOMMIE B. CHANDLER.

